A hook for new mail arrival is introduced.

wl/ChangeLog

@@ -1,3 +1,12 @@
+2017-02-04  Kazuhiro Ito  <kzhr@d1.dion.ne.jp>
+	Suggested by Pascal Haakmat <pascalh@gmail.com>
+
+	* wl-vars.el (wl-biff-new-mail-hook): New hook.
+
+	* wl-util.el (wl-biff-notify): Run wl-biff-new-mail-hook when new
+	mail has arrived.
+	Cf. [wl-en:06109], https://github.com/wanderlust/wanderlust/pull/137
+
 2017-02-04  Kazuhiro Ito  <kzhr@d1.dion.ne.jp>
 
 	* wl-util.el (wl-biff-start, wl-biff-launch-handler)

wl/wl-util.el

@@ -823,10 +823,13 @@ that `read' can handle, whenever this is possible."
 
 
 (defsubst wl-biff-notify (new-mails notify-minibuf)
-  (when (and (not wl-modeline-biff-status) (> new-mails 0))
-    (run-hooks 'wl-biff-notify-hook))
-  (when (and wl-modeline-biff-status (eq new-mails 0))
-    (run-hooks 'wl-biff-unnotify-hook))
+  (if (> new-mails 0)
+      (progn
+	(unless wl-modeline-biff-status
+	  (run-hooks 'wl-biff-notify-hook))
+	(run-hook-with-args 'wl-biff-new-mail-hook new-mails))
+    (when (and wl-modeline-biff-status (eq new-mails 0))
+      (run-hooks 'wl-biff-unnotify-hook)))
   (setq wl-modeline-biff-status (> new-mails 0))
   (force-mode-line-update t)
   (when notify-minibuf

wl/wl-vars.el

@@ -887,6 +887,10 @@ The cursor point is located at top of the body.")
   "A hook called when a biff-notification is invoked.")
 (defvar wl-biff-unnotify-hook nil
   "A hook called when a biff-notification is removed.")
+(defvar wl-biff-new-mail-hook nil
+  "A hook called when `wl-biff-notify' found non-zero new
+mails. The hook functions receive the number of new mails as
+the first argument.")
 (defvar wl-auto-check-folder-pre-hook nil
   "A hook called before auto check folders.")
 (defvar wl-auto-check-folder-hook nil